A review on the progress in cobalt removal for PDC

Abstract

As an excellent super-hard composite cutting tool material, polycrystalline diamond composite (PDC) is widely utilized in various fields such as coal geology, oil drilling and gas extraction. However, one of the main reason for its subsequent failure is the use of cobalt, which is the most commonly used metal binder during its sintering process. In recent years, researchers have conducted studies on the methods and effects of cobalt removal after sintering. This review summarizes the studies on the role and influence of cobalt in the PDC's fabrication process as well as the researches on the progress of cobalt removal from the upper layer of PDC through acid leaching or electrolysis methods. Moreover, the effects after cobalt removal on wear resistance, thermal stability and impact toughness have been discussed. The review provides a comprehensive overview of experimental results and insights derived from studies on cobalt removal of PDC over the past dozen years. The focus is on the technologies, solution formulas of cobalt removal, and the relationship between the depth and performance of PDC after cobalt removal. It is crucial to optimize these parameters for achieving efficient and precise cobalt removal, thereby optimizing the performance of PDC.